(a) Field of the Invention
The present invention relates to a photoresist composition for an MMN (multi-micro nozzle) head coater, and more particularly to a photoresist composition with improved uniformity and less stain problem which is suitable for an MMN coater for large-scale glass of the 5th generation line and that contributes to improvement in productivity and product quality.
(b) Description of the Related Art
With the increase of demand for LCD panels, especially for panels for TVs and monitors, larger glass and finer panels are required. With this trend, development of a new photoresist requiring new process conditions is needed. The photolithographic process on large-scale glass is an important process that determines line productivity. Of the coating characteristics of the photoresist film, presence of stains, contrast, resolution, adhesion to the substrate, materials remaining on the film, and so forth directly affect the qualities of circuits formed during the later etching process. Particularly, stains formed after the photoresist is coated using a coater during the photolithographic process become the cause of poor coating and CD uniformity. It remains after the PR (photoresist) has been stripped during the etching process, and thus reduces the productivity of LCD panels and lowers the product quality. For an MMN coater used in a photolithographic process for large-scale glass, the problem is more severe and a new type of stain is formed.
The MMN coater was brought into use for the following reason.
To coat a 1,100×1,250 mm glass used in the 5th generation line by a single scan, a new type of multi-micro nozzle (MMM) head is required. The nozzle has a length of 1,100 mm, with holes having a diameter of 80 μm and a pitch of 0.3 mm. The PR is sprayed through the holes of the nozzle (see FIG. 1).
This type of nozzle has the following advantages over the conventional slit & spin method: gap control between the glass and the nozzle is easy; and a waste of the PR can be greatly reduced.
However, if the PR is coated using the MMN head, a variety of stains are formed. The most troublesome among them are central stain, lateral stain, and cloudy stain (see FIG. 2).